This change adds a new flavor of dma-bufs that can be used by virtio drivers to share exported objects. A virtio dma-buf can be queried by virtio drivers to obtain the UUID which identifies the underlying exported object.

Signed-off-by: David Stevens stevensd@chromium.org --- drivers/virtio/Makefile | 2 +- drivers/virtio/virtio.c | 6 +++ drivers/virtio/virtio_dma_buf.c | 85 +++++++++++++++++++++++++++++++++ include/linux/virtio.h | 1 + include/linux/virtio_dma_buf.h | 37 ++++++++++++++ 5 files changed, 130 insertions(+), 1 deletion(-) create mode 100644 drivers/virtio/virtio_dma_buf.c create mode 100644 include/linux/virtio_dma_buf.h

diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 29a1386ecc03..ecdae5b596de 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o +obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o virtio_dma_buf.o obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index a977e32a88f2..5d46f0ded92d 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -357,6 +357,12 @@ int register_virtio_device(struct virtio_device *dev) } EXPORT_SYMBOL_GPL(register_virtio_device);

+bool is_virtio_device(struct device *dev) +{ + return dev->bus == &virtio_bus; +} +EXPORT_SYMBOL_GPL(is_virtio_device); + void unregister_virtio_device(struct virtio_device *dev) { int index = dev->index; /* save for after device release */ diff --git a/drivers/virtio/virtio_dma_buf.c b/drivers/virtio/virtio_dma_buf.c new file mode 100644 index 000000000000..45d6e8647dcf --- /dev/null +++ b/drivers/virtio/virtio_dma_buf.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * dma-bufs for virtio exported objects + * + * Copyright (C) 2020 Google, Inc. + */ + +#include <linux/virtio_dma_buf.h> + +/** + * virtio_dma_buf_export - Creates a new dma-buf for a virtio exported object + * @exp_info: [in] see dma_buf_export(). ops MUST refer to a dma_buf_ops + * struct embedded in a virtio_dma_buf_ops. + * + * This wraps dma_buf_export() to allow virtio drivers to create a dma-buf + * for an virtio exported object that can be queried by other virtio drivers + * for the object's UUID. + */ +struct dma_buf *virtio_dma_buf_export + (const struct dma_buf_export_info *exp_info) +{ + const struct virtio_dma_buf_ops *virtio_ops = + container_of(exp_info->ops, + const struct virtio_dma_buf_ops, ops); + + if (!exp_info->ops || + exp_info->ops->attach != &virtio_dma_buf_attach || + !virtio_ops->get_uuid) { + return ERR_PTR(-EINVAL); + } + + return dma_buf_export(exp_info); +} +EXPORT_SYMBOL(virtio_dma_buf_export); + +/** + * virtio_dma_buf_attach - mandatory attach callback for virtio dma-bufs + */ +int virtio_dma_buf_attach(struct dma_buf *dma_buf, + struct dma_buf_attachment *attach) +{ + int ret; + const struct virtio_dma_buf_ops *ops = + container_of(dma_buf->ops, + const struct virtio_dma_buf_ops, ops); + + if (ops->device_attach) { + ret = ops->device_attach(dma_buf, attach); + if (ret) + return ret; + } + return 0; +} +EXPORT_SYMBOL(virtio_dma_buf_attach); + +/** + * is_virtio_dma_buf - returns true if the given dma-buf is a virtio dma-buf + * @dma_buf: buffer to query + */ +bool is_virtio_dma_buf(struct dma_buf *dma_buf) +{ + return dma_buf->ops->attach == &virtio_dma_buf_attach; +} +EXPORT_SYMBOL(is_virtio_dma_buf); + +/** + * virtio_dma_buf_get_uuid - gets a virtio dma-buf's exported object's uuid + * @dma_buf: [in] buffer to query + * @uuid: [out] the uuid + * + * Returns: 0 on success, negative on failure. + */ +int virtio_dma_buf_get_uuid(struct dma_buf *dma_buf, + uuid_t *uuid) +{ + const struct virtio_dma_buf_ops *ops = + container_of(dma_buf->ops, + const struct virtio_dma_buf_ops, ops); + + if (!is_virtio_dma_buf(dma_buf)) + return -EINVAL; + + return ops->get_uuid(dma_buf, uuid); +} +EXPORT_SYMBOL(virtio_dma_buf_get_uuid); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 15f906e4a748..9397e25616c4 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -128,6 +128,7 @@ static inline struct virtio_device *dev_to_virtio(struct device *_dev) void virtio_add_status(struct virtio_device *dev, unsigned int status); int register_virtio_device(struct virtio_device *dev); void unregister_virtio_device(struct virtio_device *dev); +bool is_virtio_device(struct device *dev);

void virtio_break_device(struct virtio_device *dev);

diff --git a/include/linux/virtio_dma_buf.h b/include/linux/virtio_dma_buf.h new file mode 100644 index 000000000000..a2fdf217ac62 --- /dev/null +++ b/include/linux/virtio_dma_buf.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * dma-bufs for virtio exported objects + * + * Copyright (C) 2020 Google, Inc. + */ + +#ifndef _LINUX_VIRTIO_DMA_BUF_H +#define _LINUX_VIRTIO_DMA_BUF_H + +#include <linux/dma-buf.h> +#include <linux/uuid.h> +#include <linux/virtio.h> + +/** + * struct virtio_dma_buf_ops - operations possible on exported object dma-buf + * @ops: the base dma_buf_ops. ops.attach MUST be virtio_dma_buf_attach. + * @device_attach: [optional] callback invoked by virtio_dma_buf_attach during + * all attach operations. + * @get_uid: [required] callback to get the uuid of the exported object. + */ +struct virtio_dma_buf_ops { + struct dma_buf_ops ops; + int (*device_attach)(struct dma_buf *dma_buf, + struct dma_buf_attachment *attach); + int (*get_uuid)(struct dma_buf *dma_buf, uuid_t *uuid); +}; + +int virtio_dma_buf_attach(struct dma_buf *dma_buf, + struct dma_buf_attachment *attach); + +struct dma_buf *virtio_dma_buf_export + (const struct dma_buf_export_info *exp_info); +bool is_virtio_dma_buf(struct dma_buf *dma_buf); +int virtio_dma_buf_get_uuid(struct dma_buf *dma_buf, uuid_t *uuid); + +#endif /* _LINUX_VIRTIO_DMA_BUF_H */

Add support for UUID-based resource sharing mechanism to virtgpu. This implements the new virtgpu commands and hooks them up to dma-buf's get_uuid callback.

Signed-off-by: David Stevens stevensd@chromium.org --- drivers/gpu/drm/virtio/virtgpu_drv.c | 3 + drivers/gpu/drm/virtio/virtgpu_drv.h | 21 ++++++ drivers/gpu/drm/virtio/virtgpu_kms.c | 4 ++ drivers/gpu/drm/virtio/virtgpu_prime.c | 96 +++++++++++++++++++++++++- drivers/gpu/drm/virtio/virtgpu_vq.c | 55 +++++++++++++++ 5 files changed, 176 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c index ab4bed78e656..b039f493bda9 100644 --- a/drivers/gpu/drm/virtio/virtgpu_drv.c +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c @@ -165,6 +165,7 @@ static unsigned int features[] = { VIRTIO_GPU_F_VIRGL, #endif VIRTIO_GPU_F_EDID, + VIRTIO_GPU_F_RESOURCE_UUID, }; static struct virtio_driver virtio_gpu_driver = { .feature_table = features, @@ -202,6 +203,8 @@ static struct drm_driver driver = { .prime_handle_to_fd = drm_gem_prime_handle_to_fd, .prime_fd_to_handle = drm_gem_prime_fd_to_handle, .gem_prime_mmap = drm_gem_prime_mmap, + .gem_prime_export = virtgpu_gem_prime_export, + .gem_prime_import = virtgpu_gem_prime_import, .gem_prime_import_sg_table = virtgpu_gem_prime_import_sg_table,

.gem_create_object = virtio_gpu_create_object, diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h index 49bebdee6d91..cf54b89d9ab1 100644 --- a/drivers/gpu/drm/virtio/virtgpu_drv.h +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h @@ -49,6 +49,10 @@ #define DRIVER_MINOR 1 #define DRIVER_PATCHLEVEL 0

+#define UUID_INITIALIZING 0 +#define UUID_INITIALIZED 1 +#define UUID_INITIALIZATION_FAILED 2 + struct virtio_gpu_object_params { uint32_t format; uint32_t width; @@ -71,6 +75,9 @@ struct virtio_gpu_object { uint32_t hw_res_handle; bool dumb; bool created; + + int uuid_state; + uuid_t uuid; }; #define gem_to_virtio_gpu_obj(gobj) \ container_of((gobj), struct virtio_gpu_object, base.base) @@ -200,6 +207,7 @@ struct virtio_gpu_device { bool has_virgl_3d; bool has_edid; bool has_indirect; + bool has_resource_assign_uuid;

struct work_struct config_changed_work;

@@ -210,6 +218,9 @@ struct virtio_gpu_device { struct virtio_gpu_drv_capset *capsets; uint32_t num_capsets; struct list_head cap_cache; + + /* protects resource state when exporting */ + spinlock_t resource_export_lock; };

struct virtio_gpu_fpriv { @@ -335,6 +346,10 @@ void virtio_gpu_dequeue_fence_func(struct work_struct *work);

void virtio_gpu_notify(struct virtio_gpu_device *vgdev);

+int +virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev, + struct virtio_gpu_object_array *objs); + /* virtgpu_display.c */ void virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev); void virtio_gpu_modeset_fini(struct virtio_gpu_device *vgdev); @@ -366,6 +381,12 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev, bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo);

/* virtgpu_prime.c */ +struct dma_buf *virtgpu_gem_prime_export(struct drm_gem_object *obj, + int flags); +struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev, + struct dma_buf *buf); +int virtgpu_gem_prime_get_uuid(struct drm_gem_object *obj, + uuid_t *uuid); struct drm_gem_object *virtgpu_gem_prime_import_sg_table( struct drm_device *dev, struct dma_buf_attachment *attach, struct sg_table *sgt); diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c index 023a030ca7b9..7bcd0c75effa 100644 --- a/drivers/gpu/drm/virtio/virtgpu_kms.c +++ b/drivers/gpu/drm/virtio/virtgpu_kms.c @@ -125,6 +125,7 @@ int virtio_gpu_init(struct drm_device *dev) vgdev->dev = dev->dev;

spin_lock_init(&vgdev->display_info_lock); + spin_lock_init(&vgdev->resource_export_lock); ida_init(&vgdev->ctx_id_ida); ida_init(&vgdev->resource_ida); init_waitqueue_head(&vgdev->resp_wq); @@ -153,6 +154,9 @@ int virtio_gpu_init(struct drm_device *dev) if (virtio_has_feature(vgdev->vdev, VIRTIO_RING_F_INDIRECT_DESC)) { vgdev->has_indirect = true; } + if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_RESOURCE_UUID)) { + vgdev->has_resource_assign_uuid = true; + }

DRM_INFO("features: %cvirgl %cedid\n", vgdev->has_virgl_3d ? '+' : '-', diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c index 050d24c39a8f..acd14ef73d56 100644 --- a/drivers/gpu/drm/virtio/virtgpu_prime.c +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c @@ -23,12 +23,102 @@ */

#include <drm/drm_prime.h> +#include <linux/virtio_dma_buf.h>

#include "virtgpu_drv.h"

-/* Empty Implementations as there should not be any other driver for a virtual - * device that might share buffers with virtgpu - */ +static int virtgpu_virtio_get_uuid(struct dma_buf *buf, + uuid_t *uuid) +{ + struct drm_gem_object *obj = buf->priv; + struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj); + struct virtio_gpu_device *vgdev = obj->dev->dev_private; + + wait_event(vgdev->resp_wq, bo->uuid_state != UUID_INITIALIZING); + if (bo->uuid_state != UUID_INITIALIZED) + return -ENODEV; + + uuid_copy(uuid, &bo->uuid); + + return 0; +} + +const struct virtio_dma_buf_ops virtgpu_dmabuf_ops = { + .ops = { + .cache_sgt_mapping = true, + .attach = virtio_dma_buf_attach, + .detach = drm_gem_map_detach, + .map_dma_buf = drm_gem_map_dma_buf, + .unmap_dma_buf = drm_gem_unmap_dma_buf, + .release = drm_gem_dmabuf_release, + .mmap = drm_gem_dmabuf_mmap, + .vmap = drm_gem_dmabuf_vmap, + .vunmap = drm_gem_dmabuf_vunmap, + }, + .device_attach = drm_gem_map_attach, + .get_uuid = virtgpu_virtio_get_uuid, +}; + +struct dma_buf *virtgpu_gem_prime_export(struct drm_gem_object *obj, + int flags) +{ + struct dma_buf *buf; + struct drm_device *dev = obj->dev; + struct virtio_gpu_device *vgdev = dev->dev_private; + struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj); + struct virtio_gpu_object_array *objs; + int ret = 0; + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + + if (vgdev->has_resource_assign_uuid) { + objs = virtio_gpu_array_alloc(1); + if (!objs) + return ERR_PTR(-ENOMEM); + virtio_gpu_array_add_obj(objs, &bo->base.base); + + ret = virtio_gpu_cmd_resource_assign_uuid(vgdev, objs); + if (ret) + return ERR_PTR(ret); + virtio_gpu_notify(vgdev); + } else { + bo->uuid_state = UUID_INITIALIZATION_FAILED; + } + + exp_info.ops = &virtgpu_dmabuf_ops.ops; + exp_info.size = obj->size; + exp_info.flags = flags; + exp_info.priv = obj; + exp_info.resv = obj->resv; + + buf = virtio_dma_buf_export(&exp_info); + if (IS_ERR(buf)) + return buf; + + drm_dev_get(dev); + drm_gem_object_get(obj); + + return buf; +} + +struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev, + struct dma_buf *buf) +{ + struct drm_gem_object *obj; + + if (buf->ops == &virtgpu_dmabuf_ops.ops) { + obj = buf->priv; + if (obj->dev == dev) { + /* + * Importing dmabuf exported from our own gem increases + * refcount on gem itself instead of f_count of dmabuf. + */ + drm_gem_object_get(obj); + return obj; + } + } + + return drm_gem_prime_import(dev, buf); +}

struct drm_gem_object *virtgpu_gem_prime_import_sg_table( struct drm_device *dev, struct dma_buf_attachment *attach, diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5d9952..823223b0bb75 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -1107,3 +1107,58 @@ void virtio_gpu_cursor_ping(struct virtio_gpu_device *vgdev, memcpy(cur_p, &output->cursor, sizeof(output->cursor)); virtio_gpu_queue_cursor(vgdev, vbuf); } + +static void virtio_gpu_cmd_resource_uuid_cb(struct virtio_gpu_device *vgdev, + struct virtio_gpu_vbuffer *vbuf) +{ + struct virtio_gpu_object *obj = + gem_to_virtio_gpu_obj(vbuf->objs->objs[0]); + struct virtio_gpu_resp_resource_uuid *resp = + (struct virtio_gpu_resp_resource_uuid *)vbuf->resp_buf; + uint32_t resp_type = le32_to_cpu(resp->hdr.type); + + spin_lock(&vgdev->resource_export_lock); + WARN_ON(obj->uuid_state != UUID_INITIALIZING); + + if (resp_type == VIRTIO_GPU_RESP_OK_RESOURCE_UUID && + obj->uuid_state == UUID_INITIALIZING) { + memcpy(&obj->uuid.b, resp->uuid, sizeof(obj->uuid.b)); + obj->uuid_state = UUID_INITIALIZED; + } else { + obj->uuid_state = UUID_INITIALIZATION_FAILED; + } + spin_unlock(&vgdev->resource_export_lock); + + wake_up_all(&vgdev->resp_wq); +} + +int +virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev, + struct virtio_gpu_object_array *objs) +{ + struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(objs->objs[0]); + struct virtio_gpu_resource_assign_uuid *cmd_p; + struct virtio_gpu_vbuffer *vbuf; + struct virtio_gpu_resp_resource_uuid *resp_buf; + + resp_buf = kzalloc(sizeof(*resp_buf), GFP_KERNEL); + if (!resp_buf) { + spin_lock(&vgdev->resource_export_lock); + bo->uuid_state = UUID_INITIALIZATION_FAILED; + spin_unlock(&vgdev->resource_export_lock); + virtio_gpu_array_put_free(objs); + return -ENOMEM; + } + + cmd_p = virtio_gpu_alloc_cmd_resp + (vgdev, virtio_gpu_cmd_resource_uuid_cb, &vbuf, sizeof(*cmd_p), + sizeof(struct virtio_gpu_resp_resource_uuid), resp_buf); + memset(cmd_p, 0, sizeof(*cmd_p)); + + cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID); + cmd_p->resource_id = cpu_to_le32(bo->hw_res_handle); + + vbuf->objs = objs; + virtio_gpu_queue_ctrl_buffer(vgdev, vbuf); + return 0; +}